curl --request POST \
  --url https://api.getlago.com/api/v1/credit_notes/estimate \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "credit_note": {
    "invoice_id": "1a901a90-1a90-1a90-1a90-1a901a901a90",
    "items": [
      {
        "fee_id": "1a901a90-1a90-1a90-1a90-1a901a901a90",
        "amount_cents": 10
      },
      {
        "fee_id": "1a901a90-1a90-1a90-1a90-1a901a901a91",
        "amount_cents": 5
      }
    ]
  }
}
'

import requests

url = "https://api.getlago.com/api/v1/credit_notes/estimate"

payload = { "credit_note": {
        "invoice_id": "1a901a90-1a90-1a90-1a90-1a901a901a90",
        "items": [
            {
                "fee_id": "1a901a90-1a90-1a90-1a90-1a901a901a90",
                "amount_cents": 10
            },
            {
                "fee_id": "1a901a90-1a90-1a90-1a90-1a901a901a91",
                "amount_cents": 5
            }
        ]
    } }
headers = {
    "Authorization": "Bearer <token>",
    "Content-Type": "application/json"
}

response = requests.post(url, json=payload, headers=headers)

print(response.text)

const options = {
  method: 'POST',
  headers: {Authorization: 'Bearer <token>', 'Content-Type': 'application/json'},
  body: JSON.stringify({
    credit_note: {
      invoice_id: '1a901a90-1a90-1a90-1a90-1a901a901a90',
      items: [
        {fee_id: '1a901a90-1a90-1a90-1a90-1a901a901a90', amount_cents: 10},
        {fee_id: '1a901a90-1a90-1a90-1a90-1a901a901a91', amount_cents: 5}
      ]
    }
  })
};

fetch('https://api.getlago.com/api/v1/credit_notes/estimate', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

<?php

$curl = curl_init();

curl_setopt_array($curl, [
  CURLOPT_URL => "https://api.getlago.com/api/v1/credit_notes/estimate",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "POST",
  CURLOPT_POSTFIELDS => json_encode([
    'credit_note' => [
        'invoice_id' => '1a901a90-1a90-1a90-1a90-1a901a901a90',
        'items' => [
                [
                                'fee_id' => '1a901a90-1a90-1a90-1a90-1a901a901a90',
                                'amount_cents' => 10
                ],
                [
                                'fee_id' => '1a901a90-1a90-1a90-1a90-1a901a901a91',
                                'amount_cents' => 5
                ]
        ]
    ]
  ]),
  CURLOPT_HTTPHEADER => [
    "Authorization: Bearer <token>",
    "Content-Type: application/json"
  ],
]);

$response = curl_exec($curl);
$err = curl_error($curl);

curl_close($curl);

if ($err) {
  echo "cURL Error #:" . $err;
} else {
  echo $response;
}

package main

import (
	"fmt"
	"strings"
	"net/http"
	"io"
)

func main() {

	url := "https://api.getlago.com/api/v1/credit_notes/estimate"

	payload := strings.NewReader("{\n  \"credit_note\": {\n    \"invoice_id\": \"1a901a90-1a90-1a90-1a90-1a901a901a90\",\n    \"items\": [\n      {\n        \"fee_id\": \"1a901a90-1a90-1a90-1a90-1a901a901a90\",\n        \"amount_cents\": 10\n      },\n      {\n        \"fee_id\": \"1a901a90-1a90-1a90-1a90-1a901a901a91\",\n        \"amount_cents\": 5\n      }\n    ]\n  }\n}")

	req, _ := http.NewRequest("POST", url, payload)

	req.Header.Add("Authorization", "Bearer <token>")
	req.Header.Add("Content-Type", "application/json")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(string(body))

}

HttpResponse<String> response = Unirest.post("https://api.getlago.com/api/v1/credit_notes/estimate")
  .header("Authorization", "Bearer <token>")
  .header("Content-Type", "application/json")
  .body("{\n  \"credit_note\": {\n    \"invoice_id\": \"1a901a90-1a90-1a90-1a90-1a901a901a90\",\n    \"items\": [\n      {\n        \"fee_id\": \"1a901a90-1a90-1a90-1a90-1a901a901a90\",\n        \"amount_cents\": 10\n      },\n      {\n        \"fee_id\": \"1a901a90-1a90-1a90-1a90-1a901a901a91\",\n        \"amount_cents\": 5\n      }\n    ]\n  }\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://api.getlago.com/api/v1/credit_notes/estimate")

http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true

request = Net::HTTP::Post.new(url)
request["Authorization"] = 'Bearer <token>'
request["Content-Type"] = 'application/json'
request.body = "{\n  \"credit_note\": {\n    \"invoice_id\": \"1a901a90-1a90-1a90-1a90-1a901a901a90\",\n    \"items\": [\n      {\n        \"fee_id\": \"1a901a90-1a90-1a90-1a90-1a901a901a90\",\n        \"amount_cents\": 10\n      },\n      {\n        \"fee_id\": \"1a901a90-1a90-1a90-1a90-1a901a901a91\",\n        \"amount_cents\": 5\n      }\n    ]\n  }\n}"

response = http.request(request)
puts response.read_body

{
  "estimated_credit_note": {
    "lago_invoice_id": "1a901a90-1a90-1a90-1a90-1a901a901a90",
    "invoice_number": "LAG-1234",
    "currency": "EUR",
    "taxes_amount_cents": 20,
    "precise_taxes_amount_cents": 20.1,
    "taxes_rate": 20,
    "sub_total_excluding_taxes_amount_cents": 100,
    "max_creditable_amount_cents": 100,
    "max_refundable_amount_cents": 0,
    "max_offsettable_amount_cents": 0,
    "coupons_adjustment_amount_cents": 20,
    "precise_coupons_adjustment_amount_cents": 20.1,
    "items": [
      {
        "amount_cents": 100,
        "lago_fee_id": "1a901a90-1a90-1a90-1a90-1a901a901a90"
      }
    ],
    "applied_taxes": [
      {
        "lago_tax_id": "1a901a90-1a90-1a90-1a90-1a901a901a90",
        "tax_name": "TVA",
        "tax_code": "french_standard_vat",
        "tax_rate": 20,
        "tax_description": "French standard VAT",
        "base_amount_cents": 100,
        "amount_cents": 2000,
        "amount_currency": "USD"
      }
    ]
  }
}

{
  "status": 400,
  "error": "Bad request"
}

{
  "status": 401,
  "error": "Unauthorized"
}

{
  "status": 422,
  "error": "Unprocessable entity",
  "code": "validation_errors",
  "error_details": {}
}